Faced with a new virus like A(H1N1), there is a universal need for heightened vigilance and prompt, coordinated action. Guiding these global efforts are the International Health Regulations (IHR 2005) that were revised in the wake of SARS. The IHR (2005) has a new set of rules to support the existing global outbreak alert and response system and to make countries improve international and national surveillance and reporting mechanisms for health scares. Their aim is to help countries prevent, protect against, control and respond to the global spread of disease while avoiding unnecessary interference with international traffic and trade.

Under the IHR (2005), we have seen an unprecedented level of international cooperation against A(H1N1). Affected countries are sharing information on the genetic sequencing of the virus. Rapid diagnostic test kits have been developed and are being distributed around the world. Once an overseas traveler is confirmed to have contracted A(H1N1), a global network of contact tracing is activated to try to limit the spread of the disease.

Live virus samples have been shared with countries keen to develop a vaccine. Discussions are also underway on vaccine production and distribution in an equitable way to ensure that less developed countries can get them.

Nonetheless, these are still early days. Based on current information on A(H1N1), it is impossible to say what will happen next. The virus could fade away gradually, or mutate into something more severe. Another possibility is that we could continue to see sporadic cases emerge over the next few months, followed by a second wave when winter approaches the Northern Hemisphere.

Like the rest of the world, China cannot afford to lower its guard. The country faces three unique challenges - the sheer size of its population, the diversity in development and resources across provinces, and the large migrant population that is mobile and often falls through the cracks of public healthcare. Together with other UN agencies, WHO is ready to help China face these challenges.

China must maintain a high level of surveillance. Early detection and treatment of infected persons is the best way to check the spread of the virus and mitigate its impact. Healthcare facilities and services must be battle-ready to fight an outbreak.

Public education is another important line of defense. People at all levels of society must be informed about A(H1N1) and how to avoid human-to-human transmission through respiratory droplets. The measures are simple: Practice good personal hygiene, cover the mouth while coughing, not spit indiscriminately, wash hands frequently, avoid crowded places, stay home if you feel unwell and consult healthcare professionals for suspicious symptoms.

Just like President Hu Jintao declared a "people's war" against SARS six years ago, the public should be mobilized against this new threat. It can be done. The same voice that got ethnic minorities singing folk songs about SARS in the Guangxi Zhuang autonomous region, the same vision that put SARS messages on murals in the Inner Mongolia autonomous region, the same initiative that inspired rural students to start their own hand-washing campaign against the hand, foot and mouth disease, must all come together to develop a robust public education campaign against A (H1N1).

New infectious diseases such as A(H1N1) are emerging at the unprecedented average of one a year. Now more than ever, it is time to take public health personally.

The author is World Health Organization's representative in China.

(China Daily May 21, 2009)